Familial Hypercholesterolemia Patients Research Articles

LDLR and PCSK9 3´UTR variants and their putative effects on microRNA molecular interactions in familial hypercholesterolemia: a computational approach.

Familial hypercholesterolemia (FH) is caused by pathogenic variants in low-density lipoprotein (LDL) receptor (LDLR) or its associated genes, including apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and LDLR adaptor protein 1 (LDLRAP1). However, approximately 40% of the FH patients clinically diagnosed (based on FH phenotypes) may not carry a causal variant in a FH-related gene. Variants located at 3' untranslated region (UTR) of FH-related genes could elucidate mechanisms involved in FH pathogenesis. This study used a computational approach to assess the effects of 3'UTR variants in FH-related genes on miRNAs molecular interactions and to explore the association of these variants with molecular diagnosis of FH. Exons and regulatory regions of FH-related genes were sequenced in 83 FH patients using an exon-target gene sequencing strategy. In silico prediction tools were used to study the effects of 3´UTR variants on interactions between miRNAs and target mRNAs. Pathogenic variants in FH-related genes (molecular diagnosis) were detected in 44.6% FH patients. Among 59 3'UTR variants identified, LDLR rs5742911 and PCSK9 rs17111557 were associated with molecular diagnosis of FH, whereas LDLR rs7258146 and rs7254521 and LDLRAP1 rs397860393 had an opposite effect (p < 0.05). 3´UTR variants in LDLR (rs5742911, rs7258146, rs7254521) and PCSK9 (rs17111557) disrupt interactions with several miRNAs, and more stable bindings were found with LDLR (miR-4435, miR-509-3 and miR-502) and PCSK9 (miR-4796). LDLR and PCSK9 3´UTR variants disturb miRNA:mRNA interactions that could affect gene expression and are potentially associated with molecular diagnosis of FH.

Applications of machine learning in familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is a common hereditary cholesterol metabolic disease that usually leads to an increase in the level of low-density lipoprotein cholesterol in plasma and an increase in the risk of cardiovascular disease. The lack of disease screening and diagnosis often results in FH patients being unable to receive early intervention and treatment, which may mean early occurrence of cardiovascular disease. Thus, more requirements for FH identification and management have been proposed. Recently, machine learning (ML) has made great progress in the field of medicine, including many innovative applications in cardiovascular medicine. In this review, we discussed how ML can be used for FH screening, diagnosis and risk assessment based on different data sources, such as electronic health records, plasma lipid profiles and corneal radian images. In the future, research aimed at developing ML models with better performance and accuracy will continue to overcome the limitations of ML, provide better prediction, diagnosis and management tools for FH, and ultimately achieve the goal of early diagnosis and treatment of FH.

Treatment target achievement in patients with familial hypercholesterolemia: A real-world descriptive study

BackgroundStatin and ezetimibe represent the first line of lipid-lowering therapy in patients with familial hypercholesterolemia (FH), a disease associated with a strong cardiovascular risk. The current low-density lipoprotein cholesterol (LDL-C) target achievement rate in a real-world context using these conventional treatments has never been investigated in the Province of Quebec (Canada). ObjectiveThe primary objective of this study was to evaluate the proportion of FH patients in primary cardiovascular prevention who attained their recommended LDL-C threshold without being treated with a PCSK9 inhibitor. MethodsPatients included in this retrospective study were followed at the Lipid Clinic of the Montreal Clinical Research Institute. All patients were molecularly defined (97%) or had a definite clinical diagnosis of FH. ResultsA total of 225 patients were included in this study, of which 73% were on high-intensity statin therapy. While two-thirds of the cohort achieved the LDL-C treatment target of ≥ 50% reduction from baseline, only one third attained the target of < 2.5 mmol/L (<97 mg/dL). However, patients on high-intensity statin therapy were two times more likely to achieve the < 2.5 mmol/L targets as compared to those treated with low or moderate statin intensity (p = 0.01). There was no significant difference in treatment target achievement between men and women. ConclusionTarget achievement rate was unacceptably low in our FH patients. Conventional lipid-lowering treatments alone may not be sufficient in most FH patients to ensure adequate cardiovascular prevention.

Generation of a familial hypercholesterolemia model in non-human primate

Familial hypercholesterolemia (FH) is an inherited autosomal dominant disorder that is associated with a high plasma level of low-density lipoprotein (LDL) cholesterol, leading to an increased risk of cardiovascular diseases. To develop basic and translational research on FH, we here generated an FH model in a non-human primate (cynomolgus monkeys) by deleting the LDL receptor (LDLR) gene using the genome editing technique. Six LDLR knockout (KO) monkeys were produced, all of which were confirmed to have mutations in the LDLR gene by sequence analysis. The levels of plasma cholesterol and triglyceride were quite high in the monkeys, and were similar to those in FH patients with homozygous mutations in the LDLR gene. In addition, periocular xanthoma was observed only 1 year after birth. Lipoprotein profile analysis showed that the plasma very low-density lipoprotein and LDL were elevated, while the plasma high density lipoprotein was decreased in LDLR KO monkeys. The LDLR KO monkeys were also strongly resistant to medications for hypercholesterolemia. Taken together, we successfully generated a non-human primate model of hypercholesterolemia in which the phenotype is similar to that of homozygous FH patients.

Effects of LDLR variants rs5928, rs750518671 and rs879254797 on protein structure and functional activity in HepG2 cells transfected with CRISPR/Cas9 constructs

Familial Hypercholesterolemia (FH) is a genetic disorder associated with premature atherosclerosis and increased risk of cardiovascular diseases. LDLR deleterious mutations are associated with FH, however the role of some missense variants in FH pathogenicity remains to be elucidated. This study explored the predictive impact of LDLR missense variants on protein structure and investigated their functional effects on LDLR expression in HepG2 cells transfected with CRISPR/Cas9 constructs. FH (n = 287) and non-FH patients (n = 45) were selected, and lipid profile was obtained from medical records. LDLR variants were identified using an exon-targeted gene sequencing strategy, considering its cost-effective to increase accuracy in the identification step of the most likely FH-related variants in a less laborious process. LDLR variants were selected based on conflicting pathogenicity results found in Clinvar, in silico prediction tools, affected LDLR domains, and less common variants considering minor allele frequency < 0.05. Molecular modeling studies were used to predict the effects of LDLR missense variants on protein structure. Recombinant LDLR variants were constructed using CRISPR/Cas9 system and were used to transfect HepG2 cells. Functional assays in transfected cells were performed to assess LDLR expression using flow cytometry and western blotting, and LDLR activity using flow cytometry and confocal microscopy. The variants rs121908039 (c.551G>A, p.C184Y), rs879254797 (c.1118G>A, p.G373D), rs28941776 (c.1646G>A, p.G549D), rs750518671 (c.2389G>C, p.V797L), rs5928 (c.2441G>A, p.R814Q) and rs137853964 (c.2479G>A, p.V827I) were selected for molecular docking analysis. The p.C184Y exhibited a favorable energy change for protein stability due to its interaction with EGF-A/EGF-B regions; p.G373D and p.G549D displayed intermediate energy changes; and p.R814Q and p.V827I showed smaller energy changes. The results of functional assays showed that p.G373D, p.V797L and p.R814Q reduced LDLR expression and activity (p < 0.05). Microscopic analysis of the p.V797L and p.G373D variants revealed altered lipid localization and accumulation in transfected HepG2 cells. Carriers of p.G549D, p.V797L and p.R814Q had higher LDL cholesterol levels than non-FH group, and (p < 0.05). p.G373D and p.G549D were associated with clinical manifestations of FH. In conclusion, the p.C184Y, p.G373D, p.G549D and p.R814Q variants alter protein stability and intramolecular interactions, while p.V797L has a minimal impact on protein stability, and p.V827I has no significant intramolecular interactions. p.G373D, p.V767L and p.R814Q are associated with impaired LDLR expression and activity.

Long-term safety and effectiveness of alirocumab and evolocumab in familial hypercholesterolemia (FH) in Belgium

Background: In 2019, the European Atherosclerosis Society (EAS) published updated guidelines, recommending even lower blood cholesterol targets than previously. In patients with familial hypercholesterolaemia (FH), who have very elevated blood cholesterol levels and are at (‘Very’) ‘High risk’ of atherosclerotic cardiovascular disease (ASCVD), this represents a real challenge. Anti-Proprotein convertase subtilisin/kexin type 9 monoclonal antibody (anti-PCSK9 mAb) has been commercially available for FH in Belgium since 2015. Our study aims to investigate the real-life efficacy of anti-PCSK9 mAb in FH patients. Method: We sourced patients from the EAS FH Studies Collaboration database (an international database on FH in which Belgium participates). We only retained patients using anti-PCSK9 mAb and followed at our Lipid Clinic. Results: Of the 239 subjects included in this study (mean age: 56 years), 85% were considered at ‘Very High Risk’ (56% with a history of ASCVD), the remaining 15% were at ‘High Risk’. The PCSK9 mAb treatment reduced LDL-C levels by 54% within the first year. This reduction was maintained over the follow-up (FU) period (3.0 ± 1.8 years). The EAS targets were reached in 50% of the subjects, 93% of whom were also treated with statins. The treatment was very well tolerated. At the end of the observation period, 96% patients continued receiving PCSK9 mAb. Conclusions: Anti-PCSK9 mAb are a safe and effective therapeutic option for lowering LDL-C levels in FH patients. It allowed a significant portion of our FH patients to reach their lipid targets, mainly in those with combined therapy with statin and/or ezetimibe.

Association between Familial Hypercholesterolemia and Serum Levels of Cholesterol Synthesis and Absorption Markers: The CACHE Study FH Analysis.

Serum levels of cholesterol absorption and synthesis markers are known to be associated with cardiovascular risk. Familial hypercholesterolemia (FH) is a well-known inherited disorder presenting elevated low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) levels and premature coronary disease. In this study, we aim to examine the differences in terms of serum markers of cholesterol metabolism between FH and non-FH individuals and to examine their associations with serum lipid levels. In this study, we utilized data on serum markers of cholesterol metabolism, namely, lathosterol (Latho, synthesis marker), campesterol (Campe, absorption marker), and sitosterol (Sito, absorption marker) measured by gas chromatography of the CACHE consortium, which comprised of 13 research groups in Japan. Clinical data were compiled using REDCap system. Among the 2944 individuals in the CACHE population, we selected individuals without lipid-lowering medications and hemodialysis patients for this CACHE study FH analysis. Multivariable adjustment was performed to assess the associations. In this study, we analyzed data from 51 FH patients and 1924 non-FH individuals. After adjustment for possible confounders, the FH group was shown to have significantly higher Campe and Sito concentrations and insignificantly higher Latho concentrations than the non-FH group. These marker concentrations showed nonlinear associations with TC in the FH group. Campe/Latho and Sito/Latho ratios were significantly higher in the FH group than in the non-FH group. FH group had significantly elevated serum Campe and Sito concentrations and insignificantly elevated Latho concentrations; thus, intestinal cholesterol absorption relative to hepatic cholesterol synthesis was suggested to be elevated in patients with FH. Serum Latho, Campe, and Sito concentrations showed nonlinear associations with TC in the FH group.

Incidence of familial hypercholesterolemia in patients with early manifestations of coronary artery disease: data from a Russian multicenter study and meta-analysis

Aim. To assess the possibility of familial hypercholesterolemia (FH) detection among patients with early coronary artery disease (CAD) in practice in comparison with data from different populations. Patients with early manifestations of CAD are a promising group for identifying a proband with FH and subsequent cascade screening. The question remains open about the sufficiency of clinical criteria for diagnosing this disease.Material and methods. We examined 651 patients with CAD manifestations aged £55 years in men and £60 years in women. FH was diagnosed according to the Dutch Lipid Clinic Network (DLCN) criteria, and cardiovascular risk was assessed using the Montreal-FH-SCOR E. In 35 phenotype-positive patients with FH, as well as 5 with lowdensity lipoprotein cholesterol levels ³5,5 mmol/l and 23 with age of manifestation of coronary artery disease £35 years, the coding sequence of the genes for apolipoprotein B (APOB), low-density lipoprotein receptor (LDLR), low-density lipoprotein receptor adapter protein 1 (LDLRAP1), proprotein convertase subtilisin/kexin type 9 (PCSK9).Results. Definite FH was in 8 (1,2%), probable in 27 (4.2%), possible in 339 (52,1%) patients, while 277 (42,5%) patients had DLCN score of &lt;3 points; 31 (88,6%), of 35 phenotype-positive patients had a high Montreal-FH-SCORE risk. Six carriers of pathogenic variants were identified, 2 of which were among phenotype-negative patients. A meta-analysis of 16 studies with 13065 patients (2012-2023) showed that the incidence of FH is 5,22 (4,848-5,619)% (fixed model) and 5,93 (4,528-7,515)% (random model).Conclusion. The use of existing diagnostic scales does not provide guaranteed detection of FH among patients with early CAD. It is likely that DLCN modification by additional gradation of the criterion for the age of CAD manifestation will help increase its diagnostic value.

Long-term efficacy and safety of lerodalcibep in heterozygous familial hypercholesterolaemia: the LIBerate-HeFH trial.

Lerodalcibep, a novel small recombinant fusion protein of a PCSK9-binding domain (adnectin) and human serum albumin demonstrated highly effective low-density lipoprotein cholesterol (LDL-C) reduction with monthly 300 mg in 1.2 ml SC dosing in Phase 2. In this global Phase 3 trial, the safety and efficacy of lerodalcibep was evaluated in heterozygous familial hypercholesterolaemia (HeFH) patients requiring additional LDL-C lowering. Patients were randomized 2:1 to monthly SC injections of either lerodalcibep 300 mg or placebo for 24 weeks. The primary efficacy endpoints were the percent change from baseline in LDL-C at Week 24 and the mean of Weeks 22 and 24. In 478 randomized subjects [mean age (range); 53 (18-80) years, 51.7% female, mean (SD) baseline LDL-C 3.88 (1.66) mmol/L] lerodalcibep reduced LDL-C, compared to placebo by an absolute amount of 2.08 (0.11) mmol/L [LS mean(SE); 95% CI -2.30 to -1.87] with a percentage difference of -58.61 (3.25)% at Week 24 and by 2.28 (0.10) mmol/L (95% CI -2.47 to -2.09) with a percentage difference of -65.0 (2.87)% at the mean of Weeks 22 and 24 (P < 0.0001 for all). With lerodalcibep, 68% of subjects achieved both a reduction in LDL-C ≥ 50% and the recommended ESC LDL-C targets during the study. Except for mild injection site reactions, treatment-emergent adverse events were similar between lerodalcibep and placebo. Lerodalcibep, a novel anti-PCSK9 small binding protein dosed monthly as an alternative to monoclonal antibodies, significantly reduced LDL-C in subjects with HeFH with a safety profile similar to placebo.

Familial Hypercholesterolemia: Pitfalls and Challenges in Diagnosis and Treatment.

Familial hypercholesterolemia (FH), a condition, which is characterized by a life-long exposure to markedly elevated low-density lipoprotein (LDL) concentrations from birth, and it still remains underdiagnosed and undertreated, despite the fact that its heterogeneous form represents one of the commonest genetic disorders to date. Indeed, only 10% of all estimated affected individuals have been diagnosed worldwide and for the most of them diagnosis comes too late, when atherosclerotic cardiovascular disease (ASCVD) has already been developed. Undiagnosed and undertreated FH leads to accelerated ASCVD with a high rate of premature deaths. Recently, several novel treatment modalities have been introduced, especially for the management of severe hypercholesterolemia. Nonetheless, a substantial number of FH patients still do not achieve guideline-recommended LDL cholesterol target values. In the present review we will summarize and critically discuss pitfalls and challenges in successful diagnosis and treatment of FH.

Screening and clinical characteristics analysis of familial hypercholesterolemia in a tertiary public hospital.

Familial hypercholesterolemia (FH) is becoming a global burden. However, it remains underdiagnosed and undertreated worldwide. This study aimed to observe the screening rate of FH patients and department distribution among hospitalized patients using different diagnostic criteria. A total of 45,410 inpatients with LDL-C ≥3.5 mmol/L between 2008 and 2019 were included from The Second Affiliated Hospital of Nanchang University. Inpatients are diagnosed and divided into groups by Dutch Lipid Clinic Network (DLCN) criteria, Chinese-modified DLCN criteria and Chinese expert consensus (CEC) criteria. There were 172, 1,076 and 115 inpatients included in the DLCN group, Chinese-modified DLCN group and CEC group, respectively (screening rates: 0.38%, 2.37% and 0.25%). These FH patients had a very high risk of atherosclerotic cardiovascular disease (ASCVD) (55.7%-74.4%), especially in the DLCN group and CEC group (70.4%-74.4%). More than half of the patients were in the Department of Cardiology, and other high-risk departments included Neurology, Nephrology, Vascular Surgery, Otolaryngology & Head Neck Surgery and Traditional Chinese Medicine (24.35%-31.51%). Overall, hypertension, coronary heart disease, carotid arteriosclerosis, hepatic cyst, arrhythmia, and nonalcoholic fatty liver disease were common accompanying diseases with FH. It is necessary to establish appropriate diagnostic criteria and more positive treatment strategies for the FH inpatient population. In addition, promoting awareness of FH among doctors from other departments is also necessary. Therefore, developing a comprehensive management strategy for FH disease is very important.

Familial hypercholesterolaemia in UK primary care: a Clinical Practice Research Datalink study of an under-recognised condition.

Studies utilising genotyping methods report the prevalence of familial hypercholesterolaemia to be as high as one in 137 of the adult population. To estimate the prevalence of familial hypercholesterolaemia measured by clinically coded diagnosis, associated treatments, and lipid measurements observed in UK primary care. This was a retrospective analysis using the Clinical Practice Research Datalink (CPRD) GOLD database. Patients aged ≥18 years and actively registered on the index date (30 June 2018) formed the study cohort. Point prevalence of familial hypercholesterolaemia for 2018 was estimated overall and for each nation of the UK. Patients with familial hypercholesterolaemia were stratified into primary and secondary prevention groups, defined as those with/without a prior diagnosis of atherosclerotic cardiovascular disease. Prevalence estimates and extrapolations were replicated for these subgroups. Baseline demographic, lipid, and clinical characteristics for the prevalent cohort were presented. In total, 4048 patients with familial hypercholesterolaemia formed the study cohort. The estimated familial hypercholesterolaemia prevalence for the UK was 16.4 per 10 000 (95% confidence interval [CI] = 16.0 to 16.9). Of these, 2646 (65.4%) patients with familial hypercholesterolaemia had a recent prescription for lipid-lowering therapy. Mean lipid levels were lower for those treated with lipid-lowering therapy compared with those untreated: 5.34 mmol/L (SD 1.50) versus 6.25 mmol/L (SD 1.55) for total cholesterol and 3.15 mmol/L (SD 1.34) versus 3.96 mmol/L (SD 1.36) for low-level density lipoprotein cholesterol. The estimated prevalence of familial hypercholesterolaemia was one in 608 of the population, less than expected from other studies, which may indicate that familial hypercholesterolaemia is under-recognised in UK primary care. Over one-third of diagnosed patients were undertreated and many did not achieve target goals, placing them at risk of cardiovascular events.

Elevated sphingosine 1-phosphate level in familial hypercholesterolemic patients

Elevated sphingosine 1-phosphate level in familial hypercholesterolemic patients

Familial Hypercholesterolaemia in Children and Adolescents: Current and Future Perspectives.

Familial hypercholesterolemia (FH) is a genetic disease, the underlying cause of which is represented by mutations capable of influencing the metabolism of low-density lipoproteins (LDL). The distinguishing characteristic of FH has increased LDL cholesterol blood levels since birth, triggering early development of atherosclerosis-related diseases. Diagnosis of FH is frequently either missed or made with a considerable delay. Prompt identification of the disease is pivotal in implementing early prevention measures. Safe and effective drugs have been approved for use in children and adolescents, with statins, with or without ezetimibe, representing first-line therapy. At times, however, these medications may not be sufficient to achieve the therapeutic target, particularly in homozygous FH patients. Lipoprotein apheresis, which has proved safe and efficient, is strongly suggested in such cases. New drugs still at the investigational stage may represent a promising and personalised therapy. Lowering cholesterol levels in childhood hampers the formation of arterial atherosclerotic plaques, thus reducing cardiovascular events later in life. Accordingly, early detection, diagnosis, and therapy in FH subjects are priority aims.

Randomized, open-label, cross-over, phase-3 study to evaluate efficacy and safety of LIB003 compared with evolocumab in homozygous familial hypercholesterolaemia patients on stable lipid-lowering therapy (liberate-HOFH)

Randomized, open-label, cross-over, phase-3 study to evaluate efficacy and safety of LIB003 compared with evolocumab in homozygous familial hypercholesterolaemia patients on stable lipid-lowering therapy (liberate-HOFH)

Lomitapide for the treatment of paediatric homozygous familial hypercholesterolaemia patients - Results from the efficacy phase of the APH-19 study

Lomitapide for the treatment of paediatric homozygous familial hypercholesterolaemia patients - Results from the efficacy phase of the APH-19 study

Compliance of heterozygous familial hypercholesterolemia patients: 5-years follow-up of the Russian familial hypercholesterolemia registry

Compliance of heterozygous familial hypercholesterolemia patients: 5-years follow-up of the Russian familial hypercholesterolemia registry

Phenotype of familial hypercholesterolemia patients with acute coronary syndrome - Data from the prospective observational registry study (PRIMA-ACS)

Phenotype of familial hypercholesterolemia patients with acute coronary syndrome - Data from the prospective observational registry study (PRIMA-ACS)

Novel LDLR Variant in Familial Hypercholesterolemia: NGS-Based Identification, In Silico Characterization, and Pharmacogenetic Insights.

Familial Hypercholesterolemia (FH) is a hereditary condition that causes a rise in blood cholesterol throughout a person's life. FH can result in myocardial infarction and even sudden death if not treated. FH is thought to be caused mainly by variants in the gene for the low-density lipoprotein receptor (LDLR). This study aimed to investigate the genetic variants in FH patients, verify their pathogenicity, and comprehend the relationships between genotype and phenotype. Also, review studies assessed the relationship between the LDLR null variants and the reaction to lipid-lowering therapy. The study utilised high-throughput next-generation sequencing for genetic screening of FH-associated genes and capillary sequencing for cascade screening. Furthermore, bioinformatic analysis was employed to describe the pathogenic effects of the revealed novel variant on the structural features of the corresponding RNA molecule. We studied the clinical signs of hypercholesterolemia in a Saudi family with three generations of FH. We discovered a novel frameshift variant (c.666_670dup, p.(Asp224Alafs*43) in the LDLR and a known single nucleotide variant (c.9835A > G, p.(Ser3279Gly) in the APOB gene. It is thought that the LDLR variant causes a protein to be prematurely truncated, likely through nonsense-mediated protein decay. The LDLR variant is strongly predicted to be pathogenic in accordance with ACMG guidelines and co-segregated with the FH clinical characteristics of the family. This LDLR variant exhibited severe clinical FH phenotypes and was restricted to the LDLR protein's ligand-binding domain. According to computational functional characterization, this LDLR variant was predicted to change the free energy dynamics of the RNA molecule, thereby affecting its stability. This frameshift variant is thought to eliminate important functional domains in LDLR that are required for receptor recycling and LDL particle binding. We provide insight into how FH patients with a null variant in the LDLR gene respond to lipid-lowering therapy. The findings expand the range of FH variants and assist coronary artery disease preventive efforts by improving diagnosis, understanding the genotype-phenotype relationship, prognosis, and personalised therapy for patients with FH.

Protein structural insights into a rare PCSK9 gain-of-function variant (R496W) causing familial hypercholesterolemia in a Saudi family: whole exome sequencing and computational analysis.

Familial hypercholesterolemia (FH) is a globally underdiagnosed genetic condition associated with premature cardiovascular death. The genetic etiology data on Arab FH patients is scarce. Therefore, this study aimed to identify the genetic basis of FH in a Saudi family using whole exome sequencing (WES) and multidimensional bioinformatic analysis. Our WES findings revealed a rare heterozygous gain-of-function variant (R496W) in the exon 9 of the PCSK9 gene as a causal factor for FH in this family. This variant was absent in healthy relatives of the proband and 200 healthy normolipidemic controls from Saudi Arabia. Furthermore, this variant has not been previously reported in various regional and global population genomic variant databases. Interestingly, this variant is classified as "likely pathogenic" (PP5) based on the variant interpretation guidelines of the American College of Medical Genetics (ACMG). Computational functional characterization suggested that this variant could destabilize the native PCSK9 protein and alter its secondary and tertiary structural features. In addition, this variant was predicted to negatively influence its ligand-binding ability with LDLR and Alirocumab antibody molecules. This rare PCSK9 (R496W) variant is likely to expand our understanding of the genetic basis of FH in Saudi Arabia. This study also provides computational structural insights into the genotype-protein phenotype relationship of PCSK9 pathogenic variants and contributes to the development of personalized medicine for FH patients in the future.